78703TX
New member
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- Location
- Austin, TX
After converting my M998 into a top-drive hunting rig (photos attached) a few months ago, I'm suddenly having an issue with it starting after it worked fine for the first few months.
In order to start the rig from up top, I installed a NOS ignition switch and spliced the wiring in at the back of the existing ignition switch in the cab. It's wired exactly the same as stock, with the 24v supply to the upper ignition switch tied into the 11A wire, the run signal from the upper ignition switch tied into the 29A wire, and the start signal from the upper ignition switch tied into the 14A wire. The wire splices are right at the back of the stock ignition switch in the cab. It worked great until it didn't.
Here is what it's doing:
-When the rig is cold, it starts just fine every time.
-If I have started it, even for 30 seconds, and shut it off, it won't restart for a period of time. Sometimes 30 or more minutes. It doesn't matter if I'm trying to start it from inside the cab or from up top.
-When it's not starting, either ignition switch will warm the glow plugs and activate the gauges if I flip it to RUN. When I flip either ignition switch to START, nothing happens at all. It acts like no signal is being sent to the starter.
-In order to get it to work again, all I can do is wait. Sometimes it starts back up after 30 minutes, sometimes a few hours. This is the part that's confusing me the most. It doesn't matter which ignition switch I'm trying to use.
I have considered there may be a problem with the NSS, which I replaced with a NOS one when I had the shifter out as I was building the brackets for the push-pull cable attached to the shifter up top. Being aware of this, I have tried many times to make sure the shifter is in the Neutral position when it's not starting but it has not made a difference. The only thing that has worked to get a signal to the starter was to wait. The next thing I'll try is putting a jumper between the NSS wires to eliminate it, but unfortunately the rig is out on a ranch and I won't be able to get to it for another week.
The main point of me posting this now is because I don't know much about the control box and how the starter functions through it. I want to make sure there's not something else I need to be looking into when I get down to work on it next. I will have my voltmeter handy and will check for voltage at the starter solenoid and NSS input when it's failing to start to at least verify where the voltage is failing to get through.
Any help is much appreciated!
In order to start the rig from up top, I installed a NOS ignition switch and spliced the wiring in at the back of the existing ignition switch in the cab. It's wired exactly the same as stock, with the 24v supply to the upper ignition switch tied into the 11A wire, the run signal from the upper ignition switch tied into the 29A wire, and the start signal from the upper ignition switch tied into the 14A wire. The wire splices are right at the back of the stock ignition switch in the cab. It worked great until it didn't.
Here is what it's doing:
-When the rig is cold, it starts just fine every time.
-If I have started it, even for 30 seconds, and shut it off, it won't restart for a period of time. Sometimes 30 or more minutes. It doesn't matter if I'm trying to start it from inside the cab or from up top.
-When it's not starting, either ignition switch will warm the glow plugs and activate the gauges if I flip it to RUN. When I flip either ignition switch to START, nothing happens at all. It acts like no signal is being sent to the starter.
-In order to get it to work again, all I can do is wait. Sometimes it starts back up after 30 minutes, sometimes a few hours. This is the part that's confusing me the most. It doesn't matter which ignition switch I'm trying to use.
I have considered there may be a problem with the NSS, which I replaced with a NOS one when I had the shifter out as I was building the brackets for the push-pull cable attached to the shifter up top. Being aware of this, I have tried many times to make sure the shifter is in the Neutral position when it's not starting but it has not made a difference. The only thing that has worked to get a signal to the starter was to wait. The next thing I'll try is putting a jumper between the NSS wires to eliminate it, but unfortunately the rig is out on a ranch and I won't be able to get to it for another week.
The main point of me posting this now is because I don't know much about the control box and how the starter functions through it. I want to make sure there's not something else I need to be looking into when I get down to work on it next. I will have my voltmeter handy and will check for voltage at the starter solenoid and NSS input when it's failing to start to at least verify where the voltage is failing to get through.
Any help is much appreciated!
